forces in afghanistan. he met with american troops in the war zone, and just two weeks before heading home to take on his new job as cia director, he spoke one on one with nbc about america's mission. >> happy fourth of july to all of you. >> reporter: it's his eighth fourth of july in a combat zone, but the last in uniform for general david petraeus. he spent the day visiting some of the thousands of u.s. troops stationed in afghanistan. a farewell tour for a general many consider a rock star who found himself asking these tough as nails troops to just relax. >> the best way to relax is to put your hands in your pockets. that means you right there. go ahead. in fact, i'll put them in my pockets, too, here. >> reporter: credited with helping turn the iraq war around, petraeus was tapped by president obama a year ago to do the same in afghanistan. he admits it hasn't been easy. >> i never felt we could flip afghanistan the way we were able to flip iraq. >> reporter: a tough situation, but he insists not hope